Folded sheet-opening machine

ABSTRACT

Folded sheets are stacked on a stack magazine. A suction head locates the bottom sheet in position to be gripped by a pulling drum and the gripped sheet is conveyed around the periphery of the drum until the edge of the folded sheet engages a stopping means which prevents further conveyance of the sheet. Then, a pair of suction rollers located below the pulling drum engage the other end of the sheet and conduct the sheet therebetween and separate the ends of the sheet, thereby opening the sheet. A clamp-grab mechanism arranged below the suction rollers them grips the separated ends of the sheet and places the opened sheet upon a sheet-receiving saddle.

United States Patent Inventor Rudolf Gorig Muhlstrasse 34, 7067 Grunbach, Germany Appl. No. 837,020 Filed June 27, 1969 Patented Mar. 30, 1971 Priority July 5, 1968 Germany P 17 A61 771.9

FOLDED SHEET-OPENING MACHINE 2,568,604 9/l95l Bechberger 2,845,264 7/l958 Faeber ABSTRACT: Folded sheets are stacked on a stack magazine. A suction head locates the bottom sheet in position to be gripped by a pulling drum and the gripped sheet is conveyed around the periphery of the drum until the edge of the folded sheet engages a stopping means which prevents further conveyance of the sheet. Then, a pair of suction rollers located below the pulling drum engage the other end of the sheet and conduct the sheet therebetween and separate the ends of the sheet, thereby opening the sheet. A clamp-grab mechanism arranged below the suction rollers then grips the separated ends of the sheet and places the opened sheet upon a sheet-receiving saddle.

Patented March 3o, 1971 i 3,572,684

4 Sheets-Sheet l Fig. 1

\- @aan O 21 Inventor 20ML/f GOP/6 i wwf Patented March so, 1971 3,572,684

4 Sheets-Sheet 2 Patented March 30, 1971 3,572,684

4 Sheets-Sheet 5 Patented March 30, 1971 3,572,684

4 Sheets-Sheet 4 FOLDED SHEET-OPENING MACHINE The invention relates to a sheet feeder for collating machines, stapling machines and the like, in which a plurality of folded sheets are extracted from a movable stack magazine, opened or unfolded and fed to a paper-receiving saddle.

In known feeders of this type, the individual sheets, after being opened by means of suction shafts, are allowed to freely fall over the paper-receiving saddle of the stapling machine or the like. This type of operation frequently leads to problems and unreliable operation, particularly when used with thin paper or other inconvenient paper formats. Moreover, in the known machines, extremely small formats of approximately 70 X 100 mm. (pocket-calendar format) are virtually impossible to process, since due to the low weight of these small sheets, the paper, in free fall, would only seldom fall on the receiving saddle.

Therefore, it is an object of the present invention to provide a sheet-feeding machine for handling folded sheets, which will insure proper guidance of the sheets of paper in a positive manner from the stack magazine through to the placement thereof on the receiving saddle of the stapling machine or the like. ln this manner maximal operative security at a high production rate is attainable. l

It is a further object of the present invention to provide a feeder having the capability of handling a wide choice of formats, including extremely large or small formats.

SUMMARY OF THE INVENTION In accordance with the present invention, a feeding machine for opening a plurality of folded sheets which are stacked in a stack magazine and for placing them upon a sheet-receiving saddle includes a generally cylindrically shaped rotatable pulling drum located below the stack magazine, controllable clamps being attached to the drum for gripping a sheet coming out of the stack magazine. The sheet is conveyed around the periphery of the drum until an edge thereof abuts a movable stopping means which is located about the periphery of the drum and which prevents further conveyance ofthe sheet by the drum. A pair of suction rollers, located below the pulling drum engage the other end of the sheet and conduct the sheet therebetween. The suction rollers separate the ends of the folded sheet as it is conducted between the rollers, thereby opening the sheet. Arranged below the suction rollers is a clamp-grab mechanism for gripping the separated ends of the sheet for placing the opened sheet upon the sheet-receiving saddle.

In the feeder of the present invention the sheet is positively guided along its entire route from the stack magazine to the paper-receiving saddle of the stapling machine, collating machine, or the like, so that reliable placement on the saddle is insured. There is no reliance upon gravity alone to place the sheet on the saddle. Through appropriate adjustment of the angular rotation of the suction rollers, of the disposition of the movable plate as well as of the effective operational course of the clamp-grab mechanism, adaptation to all format size may be attained. Since the operation of all of the elements is coordinated, maximal operative security is guaranteed.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. l illustrates a schematic side view of a feeder according to this invention;

FIG. 2 illustrates a schematic side view in the direction of the arrow A of the arrangement shown in FIG. l;

FIGS. 3 5 illustrate the pulling drum and the suction rollers of the feeder of FIG. 1 in various positions in the course of a work cycle; and y FIG. 6 illustrates a clamp-grab device for the feeder shown in FIG. ll.

DESCRIPTION OF PREFERRED EMBODIMENT Referring to FIG. l, a stack magazine I, which is adjustable to accommodate various sheet sizes and fonnats, contains folded sheets 2 stacked flat on top of one another on a horizontal platform 3. The folded edge of the sheets are located adjacent to an opening 4 in the platform, the opening 4 being located at the forward end of the bottom of the stack of sheets. Below opening l a swivel-mounted suction head 6 is arranged on a rotary shaft 5. The shaft 5 is rotated by means not shown (in the manner illustrated in FIG. l), applying suction near the folded edge of the bottom-lying sheet and pulling it downwards. Suction is applied to suction head 6 in a wellknown manner which is not shown herein.

Beneath stack magazine 1 is a rotatable pulling drum 8, preferably consisting of several adjacently arranged discs 7 (see FIG. 2) mounted on a rotatable horizontal shaft 9. Guide plates lll and 13 are mounted about the periphery of pulling drum 8. Clamping meansin the form of clamps 10 are attached around the periphery of the pulling drum 8. In the illus trated embodiment, each disc 7 has a clamp 10 secured thereto (see FIG. 2). Clamps l0 are controlled in dependence on the momentary angular position of the pulling drum 8 and grip the top folded'portion of the sheet after it is pulled down by suction head 6 in the manner shown in FIG. l, so that the sheet, through the ensuing counterclockwise revolution of pulling drum 8, is drawn around the periphery of the pulling drum 8, and extracted from stack magazine 1. The sheet is at this point drawn between the opening between the surface of the drum 8 and guide plate Il.

Transport rollers 12 are arranged about the periphery of pulling drum 8 so that the sheet grasped by clamps 10 arrives, after a rotation of pulling drum 8,within the sphere of these transport rollers I2. After the delivery of the sheet to the transport rollers 12, the clamps 10 release the sheet. Transport rollers 12 revolve so as to further transport the sheet freed from clamps l0 on through the space between guide plate 13 and the periphery of pulling drum 3 to a movable plate (or stopping means) 14, against which the top (or folded edge) of the sheet abuts. This prevents the sheet from travelling further about the periphery of drum 8.

The sheet then assumes approximately the position depicted in FIG. 3. Because its edge 1S, opposite the folded edge lying against the plate 14, is no longer maintained in position by guide plate 11, it will project out from the surface of the drum 8 in somewhat the manner depicted in FIG. 3.

Below pulling drum 8 two suction rollers 16 and 17 are rotataby arranged. Suction rollers 16 and 17 are arranged so that their rotary movement is mutually dependent as well as dependent on the rotary movement of pulling drum 8. At respective points on their peripheries, suction heads 18 are mounted. Suction roller 17 includes in addition, by the formation of an empty space 19 therein, finger member 20, which in conjunction with suction head 18 is arranged in such a way that further clockwise rotation of suction roller 17 from the position shown in FIG. 3 to the position shown in FIG. 4 causes the free edge 1S of the sheet 2 to be pressed downward by finger 20. v

Thereby, the sheet edge 15 comes, by means of the further rotation of the twoisuction rollers I6 and 17, to be engaged between the two rollers 16 and I7 and to be further engaged by suction heads 18. Suction heads 18 suck up the portion of the sheet momentarily engaged therewith and in the course of further rotary motion of rollers 16 and 17 open the sheet in the manner represented in FIG. 5.

BElow the two suction rollers 16 and 17 is arranged a clamp-grab mechanism 21 (FIG. 1) which extends on either side of the sheet receiving saddle 22 of the stapling machine, collating machine or the like. Clamp-grab mechanism 2l consists essentially of two chains or belts 25 conducted over two driven pulleys or rollers, 23 and 24 respectively. The drive means for the rollers 23 and 24 is not shown herein. The chains or belts 25 extend obliquely outwards in a diverging relationship relative to saddle 22 which projects between them. The chains or belts 25 carry clamp-grabs 26. Clampgrabs 26 of which one is represented in detail in FIG. 6, are controlled by cams 27 and 28 which are coupled to the drive means for pulleys 23 and 24 by means not shown. Clampgrabs 26 grip the edges of sheet 2 opened by suction rollers 16 and 17 and conduct the sheet, as shown in FIG. l, positively and securely downwards onto saddle 22.

The clamp-grabs 26 are appropriately movable (by means not shown) and the clamp-grab mechanism 2l is adjustable in the direction of the arrows 30 in FIG. 1 for adaptation of the present machine to different sheet sizes and formats.

To further adjust the mechanism of the present invention to handle sheets of various sizes and formats, the position of the plate or stop means 14 is adjustable. This varies the point during the rotation of the drum 8 at which further movement of the sheet is blocked, thereby enabling the system to handle different size sheets. Also, the rate of rotation of suction rollers 16 and 17 is made variable.

In order to further improve the operation of the apparatus of the present invention, each of the suction rollers 16 and 17 may be provided with thin rubber rings 29 (FIG. l) on their periphery to improve the transmission of the sheet therebetween. Alternatively the surfaces of rollers 16 and 17 may be completely rubberized or covered with equivalent material.

It is pointed out that the various drive and control elements of the present invention have not been illustrated herein so as not to unduly obscure the present inventive concept. All of the various rollers, drums, and clamp means are operated in synchronism by making use of various well-known drive apparatus and techniques. A detailed description of the drive and control means for the illustrated embodiment has not been given since the fabrication' thereof should be apparent to one skilled in the art in view of the foregoing description of the present invention.

The foregoing description of a preferred embodiment of the present invention was given with respect to folded sheets which define a closed end at the top thereof, the closed end being gripped in the first instance by the suction head 6 and then by the clamping means 10 of the pulling drum 8. These sheets are also known as right-angle folded sheets. In contrast hereto there are sheet assemblies consisting of a number of folded sheets which are inserted one into the other without interconnection between the individual sheets. These assemblies are colled inserted sheets" for the purpose of this application. When the apparatus is used with inserted sheets, it is imperative that all of the sheets on each side of their joint be gripped concomitantly. This cannot be achieved by the suction heads 18, since these can only act on the innermost sheet. Therefore, in this case mechanical clamping means are used for opening these inserted sheets. Said clamping means consist of two identical clamp mechanisms 3l, one of them being provided on roller 16 and the other on roller 17. The operation of these clamp mechanisms 31 is synchronized with the other elements of the system by means not shown. They grip the sheets against the surface of roller 16 and roller 17, respectively, in a manner similar to the way clamp 10 grips a sheet against pulling drum 8. In order to ensure proper operation the inserted sheets are folded with a protruding margin of approximately mm. on one side of the joint, while the clamp mechanisms 3l are so distributed on the surface of roller 16 and roller 17, respectively, and activated in such a timed relationship that the protruding margin is gripped a few instances earlier than the sheets on the other side of the joint. Besides, when using the apparatus for inserted sheets, the suction heads 18 are inactivated.

[claim: l. Feeding machine for opening a plurality of folded sheets (2) which are stacked in a stack magazine (l) and for placing them upon a sheet-receiving saddle (22), comprising:

a generally cylindrically shaped, rotatable, pulling drum (8) located below said stack magazine (1);

controllable clamping means attached to said drum (8) for gripping a sheet (2) at its folded edge coming out of said stack magazine (l) and conveying said sheet (2) around the periphery of said drum (8), the operation of said clamping means (10) being dependent on the angular position of said drum (8);

movable stopping means (14) located about the periphery of said pulling drum (8) for engaging said sheet to prevent further conveyance thereof by said drum (8);

a pair of rotatable suction rollers (16, 17) located below said pulling drum (8), at least one of said suction rollers including a guide element (20) for engaging the other end (15, FIGS. 3 and 4) of said sheet (2) for conducting said sheet (2) therebetween and for separating the ends of said sheet 2), thereby opening said sheet; and

a clamp-grab mechanism (21) arranged below said suction rollers (16, 17) for gripping said separated ends of said sheet and for placing the opened sheet upon a sheetreceiving saddle (22).

2. Feeder according to claim l, wherein said guide element is an extending finger (20) formed in one of said suction rollers (16, 17).

3. Feeder according to claim 1, wherein said clamping means (10) comprises a plurality of clamps.

4. Feeder according to claim l, wherein an opening (4) is formed in the bottom of said stack magazine and further cornprising a downward-pulling swivel-mounted suction head (6) arranged below said opening (4) in said stack magazine (l) for locating a sheet in position to be gripped by said clamping means (10).

5. Feeder according to claim l, further comprising at least one transport roller (12) arranged adjacent the periphery of said pulling drum (8).

6. Feeder according to claim 5, further comprising two guide plates (1l, 13) at least partially enclosing an opening around the periphery of said pulling drum (8) to aid in conveyance of said sheet by said pulling drum (8).

7. Feeder according to claim l, wherein said clamp-grab mechanism (21) comprises two revolving endless chains or belts (25) on which are located cam-operated clamp-grabs (26), each of said chain or belt being located on either side of said saddle (22) and diverging obliquely therefrom, the operation of said chains or belts and of said clamp-grabs being synchronized with the motion of said suction rollers 16, 17).

8. Feeder according to claim 7, wherein said clamp-grab mechanism (2l) is movable relative to said saddle (22).

9. Feeder according to claim 7, wherein said clamp-grabs (26) are movable relative to said chains or belts (25).

10. Feeder according to claim 7, wherein said clamp-grabs (26) are movable relative to said saddle (22).

1I. Feeder according to claim 1, wherein at least a portion of the peripheral surface of said suction rollers (16, 17) is provided with rubber (29) thereon to aid in conducting said sheets therebetween.

12. Feeder according to claim l, wherein said clamping means (10) is arranged to release said gripped sheet after said sheet is conveyed to a predetermined position around the periphery of said pulling drum (8), and further comprising at least one transport roller (12) for engaging said sheet between said drum (8) and said at least one transport roller (l2) when said sheet is released by said clamping means (10).

13. Feeder according to claim l, wherein said pulling drum (8) comprises a plurality of spaced-apart discs (7) mounted on a common shaft (9).

14. Feeder according to claim 13, wherein said clamping means (l0) includes a plurality of cam-operated clamps, each of said clamps being mounted on a respective one of said discs (7).

15. Feeder according to claim l, wherein said suction rollers (16, 17) engage the other end of said sheet after said sheet has engaged said movable stopping means (14).

16. Feeder according to claim 1, wherein at least one of said suction rollers (16) has an additional clamp (S (3l) arranged thereon for gripping the edge of the sheet, said additional clamp being controlled in dependence on the angular position of said at least one suction roller. 

1. Feeding machine for opening a plurality of folded sheets (2) which are stacked in a stack magazine (1) and for placing them upon a sheet-receiving saddle (22), comprising: a generally cylindrically shaped, rotatable, pulling drum (8) located below said stack magazine (1); controllable clamping means (10) attached to said drum (8) for gripping a sheet (2) at its folded edge coming out of said stack magazine (1) and conveying said sheet (2) around the periphery of said drum (8), the operation of said clamping means (10) being dependent on the angular position of said drum (8); movable stopping means (14) located about the periphery of said pulling drum (8) for engaging said sheet to prevent further conveyance thereof by said drum (8); a pair of rotatable suction rollers (16, 17) located below said pulling drum (8), at least one of said suction rollers including a guide element (20) for engaging the other end (15, FIGS. 3 and 4) of said sheet (2) for conducting said sheet (2) therebetween and for separating the ends of said sheet (2), thereby opening said sheet; and a clamp-grab mechanism (21) arranged below said suction rollers (16, 17) for gripping said separated ends of said sheet and for placing the opened sheet upon a sheet-receiving saddle (22).
 2. Feeder according to claim 1, wherein said guide element is an extending finger (20) formed in one of said suction rollers (16, 17).
 3. Feeder according to claim 1, wherein said clamping means (10) comprises a plurality of clamps.
 4. Feeder according to claim 1, wherein an opening (4) is formed in the bottom of said stack magazine and further comprising a downward-pulling swivel-mounted suction head (6) arranged below said opening (4) in said stack magazine (1) for locating a sheet in position to be gripped by said clamping means (10).
 5. Feeder according to claim 1, further comprising at least one transport roller (12) arranged adjacent the periphery of said pulling drum (8).
 6. Feeder according to claim 5, further comprising two guide plates (11, 13) at least partially enclosing an opening around the periphery of said pulling drum (8) to aid in conveyance of said sheet by said pulling drum (8).
 7. Feeder according to claim 1, wherein said clamp-grab mechanism (21) comprises two revolving endless chains or belts (25) on which are located cam-operated clamp-grabs (26), each of said chain or belt being located on either side of said saddle (22) and diverging obliquely therefrom, the operation of said chains or belts and of said clamp-grabs being synchronized with the motion of said suction rollers (16, 17).
 8. Feeder according to claim 7, wherein said clamp-grab mechanism (21) is movable relative to said saddle (22).
 9. Feeder according to claim 7, wherein said clamp-grabs (26) are movable relative to said chains or belts (25).
 10. Feeder according to claim 7, wherein said clamp-grabs (26) are movable relative to said saddle (22).
 11. Feeder according to claim 1, wherein at least a portion of the peripheral surface of said suction rollers (16, 17) is provideD with rubber (29) thereon to aid in conducting said sheets therebetween.
 12. Feeder according to claim 1, wherein said clamping means (10) is arranged to release said gripped sheet after said sheet is conveyed to a predetermined position around the periphery of said pulling drum (8), and further comprising at least one transport roller (12) for engaging said sheet between said drum (8) and said at least one transport roller (12) when said sheet is released by said clamping means (10).
 13. Feeder according to claim 1, wherein said pulling drum (8) comprises a plurality of spaced-apart discs (7) mounted on a common shaft (9).
 14. Feeder according to claim 13, wherein said clamping means (10) includes a plurality of cam-operated clamps, each of said clamps being mounted on a respective one of said discs (7).
 15. Feeder according to claim 1, wherein said suction rollers (16, 17) engage the other end of said sheet after said sheet has engaged said movable stopping means (14).
 16. Feeder according to claim 1, wherein at least one of said suction rollers (16) has an additional clamp (S (31) arranged thereon for gripping the edge of the sheet, said additional clamp being controlled in dependence on the angular position of said at least one suction roller. 